I believe you meant to say is instead on us and that would mean a spelling pattern is a repeated form
Switching from chains to cables in the building of roller coasters was important because cables are less likely to snap when hauling several tons of roller coaster cars full of people. Chains are made of linked, welded pieces of metal that can easily snap if they pull too much. Cables, while they can snap, are much less likely to do so, because they're a stretch of fibers, be it metal or other, without any potential weak spots.
The purpose of flipping through a literature anthology isi to help you :
Generate Topic
This will potentially served as your cube of inspiration from your literature
Hope this helps